Pfizer Faces Lawsuits Over Viagra Melanoma Risk

Men who take Viagra are at higher risk for developing melanoma, and a California Viagra user who developed melanoma has filed a lawsuit against Pfizer, the maker of Viagra (sildenafil).

The lawsuit, filed in California federal court, claims that Pfizer failed to warn Viagra users of studies that connect the blockbuster erectile dysfunction drug to increased melanoma risk, Law360 reports. The plaintiff in the suit claims he would not have taken Viagra if he had been aware of the connection. The drug worked to treat his erectile dysfunction, but he said the melanoma risk far outweighs the benefits.

The man who filed the lawsuit had been taking Viagra for about five years when he discovered a large mark on his shoulder. After two biopsies, his doctor diagnosed the mark as melanoma, the most dangerous form of skin cancer. The man took Viagra for at least two more years before he became aware of studies in the Journal of the American Medical Association and other publications about the melanoma risk. The legal complaint says that despite “significant findings, Pfizer has made no efforts in its ubiquitous Viagra advertisements to warn users about the potential risk of developing melanoma that has been scientifically linked to its drug.” Law360 reports that 13 similar lawsuits have been filed and more than two dozen others are pending across the country.

The National Cancer Institute—part of the National Institutes of Health—explains that melanoma is more likely than other skin cancers to spread to other parts of the body, causing further tissue damage and complicating the potential for effective treatment and eradication of the cancerous cells.

Viagra works by inhibiting the secretion of a specific enzyme that can prevent erection. Studies from 2011, 2012 and 2014 found that blocking the enzyme can trigger the creation of melanoma cells. The most recent study cited in the suit looked at nearly 26,000 men in the United States who take Viagra and found that the melanoma risk for recent users increased by 84 percent, compared with the risk for nonusers. But melanoma is not listed among possible side effects of Viagra.

The California man has endured numerous surgeries—and the associated medical costs—and he expects to have more melanoma-related bills in the future. The lawsuit seeks actual and punitive damages and injunctive relief. No man who is prescribed Viagra “would believe or be expected to know that his use of Viagra would expose him to an increased risk of developing melanoma or exacerbating the growth of melanocytes [skin cancer cells] already present in his body,” according to the legal complaint.

The JAMA study published in June 2014 reported that among 25,848 participants, recent sildenafil users at baseline had a significantly elevated risk of invasive melanoma, with a “hazard ratio” of 1.84. Study participants who had recently used sildenafil exhibited an 84 percent increase in risk of developing or encouraging invasive melanoma.

The legal complaint says Pfizer “purposefully downplayed, understated and outright ignored the melanoma-related health hazards and risks associated with using Viagra.” Further, the drug maker “deceived potential Viagra users” by relaying positive information through the press, including testimonials from retired popular politicians, while downplaying known adverse health effects.